


Seal it with a Kiss

by OverMyFreckledBody



Category: Gravity Falls
Genre: Ambiguous/Open Ending, Bill Cipher Possessing Mabel Pines, Bill Cipher is a Jerk, Bill likes being in Dipper's body, M/M, Mabill, Non-Consensual Kissing, Poor Dipper, Pseudo-Incest, a little badwrong, non-consensual incest, not enough incest for ppl who want that but too much for ppl who dont
Language: English
Status: Completed
Published: 2020-05-24
Updated: 2020-05-24
Packaged: 2021-03-03 11:02:12
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,042
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24349972
Author URL: https://archiveofourown.org/users/OverMyFreckledBody/pseuds/OverMyFreckledBody
Summary: "You kiss your sister with that mouth?"
Relationships: Bill Cipher/Dipper Pines, Dipper Pines & Mabel Pines
Comments: 6
Kudos: 30





	Seal it with a Kiss

**Author's Note:**

> please double check those tags lmfao

A nightmare. That’s what this has to be. Any second now, Dipper is going to wake up, heart pounding, and shirt sweat-stuck to his chest. Any second now, come on…

Taking a step back from the star of the horror show, Dipper reaches back to discreetly pinch himself. Nothing. Just a brief flare of pain. No gasping, shuddering breath as he comes back to the land of the living.

This _cannot_ be real.

Standing in front of him is Mabel – well, no. Not entirely. A kind of Mabel, a semi-Mabel. A Mabel in body but not in mind.

In front of him is Bill and Mabel. Babel? Mill? Mabill?

Bill has possessed his sister and Dipper has no idea where her consciousness (soul?) is at. If what happened was anything like what happened to Dipper, she’s got to be around here somewhere. Now, if only he could find her a host of some kind…

“You should really see the look on your face!” Bill – Mabel? – laughs, drawing back Dipper’s attention. Every step he takes backwards is followed by his possessed sister. Soon enough he’s going to hit a wall or a tree or trip and then what will he do?

The person – not-person – in front of him pauses as if in thought and then a sunny grin (Dipper wants to gag at that expression on Mabel’s face, but not made by her at all) lights up the face. “Here, I’ll show you!”

Said grin very quickly, very easily melts into a contortion of horror and shock and Dipper’s stomach drops at the sight of it on instinct. Even if he knows Bill is just toying with him, he still has that knee-jerk feeling in response to seeing his sister scared and upset. It’s almost a good thing when the too bright smile comes back at Dipper’s expense.

“So scared, I can _hear_ the bullets you’re sweating from over here, Pine Tree!”

Dipper doesn’t waste any time doubting that. But he does instead try, “Get out of her, Bill! Let her go and –”

Mabel’s finger comes up to wag at Dipper as if he’s a dog begging for a scrap of food. “No can do, kiddo! I’m kind of liking this joyride; I’m not about to just give it up. Well,” pausing, Mabel’s eyelids hood and something almost… lecherous sinks into her – not hers? – smile. Dipper shivers at it. “Not without something else to take for a ride instead.”

Dipper watches his sister’s tongue run along the seam of her lips. He isn’t sure exactly how to feel about it. Other than disgust and horror, which he already has in spades.

“I don’t know what you said to trick her,” Dipper argues, pushing aside whatever… _that_ was as he focuses on the bigger issue here. “But don’t think—”

Before Dipper can tell Bill that they’ve beat him once and they can do it again, he’s interrupted by Mabel’s body laughing again. Mabel’s hands spread in front of her. “Whoa, whoa! Alright, before you get too ahead of yourself Mr. Hero, let me tell you one, little,” Mabel’s fingers pinch and she – Bill – winks, “tiny detail.”

Mabel leans forward and Dipper hurriedly steps back. She grins.

“Shooting Star here already gave me all the permission I needed to get in this thing.” A hand runs down the front of Mabel’s shirt and Dipper bites his tongue to keep himself from jumping forward and ripping it away. “No tricks, no fancy words, no loopholes. One hundred percent, bona fide _consent_.”

Dipper’s heart drops into his stomach.

Well, shoot.

Okay, not impossible – and Bill’s a liar. Bill’s a _great_ liar! So, probably a lie, but even if it was true, it doesn’t matter. Because a deal would make things a little harder, sure, but Dipper has faith that they can find some way out of this. They always do. Mystery Twins forever.

“Amazing, what things you meat sacks will give up when someone threaten one of your favorite people,” Mabel’s voice states, nonchalant, as Dipper grits his teeth. He tries not to think about just who Bill taunted her with. Mabel’s head cocks to the side. “Still, as fun as this body is…” Mabel’s tongue swipes along her teeth. “And, boy, is it _fun_ …”

Dipper’s fists clench.

“I am willing to make a trade.”

He shouldn’t be as excited to hear those words as he is. He knows he needs to be cautious and exceedingly careful about how he words this deal – if he should even make it in the first place – but…

Freeing Mabel. Of course he’s going to do it.

Bill must see the temptation his words cause Dipper, because Mabel’s lips split into a grin once more. Under Bill’s control, she steps forward, but Dipper doesn’t step back this time. The grin grows wider.

Mabel leans in again and Dipper’s breath catches at the familiar bubblegum scent that wafts from her hair. Mabel’s eyes seek his out. They’re hooded again. Dipper is starting to feel uneasy about what’s about to be said –

“You see… your body is the one I really want.”

Dipper freezes.

That.. _threat_ … it’s a weird one to word like that. It’s so awkward, strangely… _sexual_.

It gives Dipper goosebumps and his blood runs cold. He’s not exactly loving the implication of what Bill might want from him. However, he knows that it’s a façade, easily shattered as it is, it only exists to rile him up. Dipper knows that what Bill really wants is to stop them.

Which means that if he wants Dipper’s body so bad, it’s because he’s trying to thwart Dipper before he can come up with any plans to fight back. He wants to put Dipper on disadvantage.

He doesn’t think Mabel will be able to stop him on her own, but he thinks that _Dipper_ can.

And now, Dipper is starting to come up with a plan of his own.

Just as Dipper is coming to this realization, Bill – Mabel – starts to say, faux-casual, “Have you ever heard the sound of bones snapping?”

Dipper’s attention whips back to the present.

“None of that horror movie nonsense, _real_ bones cracking, breaking, bending to the point of no return?” Dipper’s heart stops. “Despite what Hollywood tries to sell you all, it is not the sound of someone biting into a pickle. Close,” one finger lifts up. “But not the same.”

Then, that finger is being held by Mabel’s other hand. It begins to be pulled back, more and more pressure being put on it. Dipper reacts to it – probably just as Bill wanted him to – immediately.

“Okay, okay!” He barely stops himself from jumping forward and pulling those hands apart. They stop, hovering in the air between the two of them. “I’ll make a deal with you.”

He feels an instant bolt of regret the second the words leave his mouth. It worsens when Bill uses Mabel’s face to smile, too big, once again.

Wow, he is so stupid. But what else is going to do? Watch Bill hurt his sister? No way.

Besides, they can do this. Dipper is just going to have to find some puppet, but they can totally do this. They’ll find a way, just like they did before, just like they always do. They can do this. They’re the Mystery Twins.

Dipper can’t imagine _ever_ not doing something like this for her. He just can’t.

Time for the demands. He licks his lips, trying to think, but it’s hard to when he hears Mabel – Bill – humming the countdown music from _Jeapardy!_. The fingers start to push against each other again.

“No hurting anybody!” Dipper blurts and then quickly continues, “You can’t use me to hurt or maim or kill anybody, including my own body. And my body is a temporary host. One time use.”

Mabel, who had previously been rubbing her chin in contemplation of Dipper’s requirements, stops. Slants a thin look at Dipper and says back, “For this deal.”

“Sure,” Dipper says, just as wary. “I’m not likely to make another one with you, anyway.”

Surprisingly, or maybe not so, this gets another smile. “Don’t sound so sure about that, kid. You’re making one with me now, aren’t you?”

When Dipper glares, the grin gets a little more teeth.

“Don’t push it,” Dipper spits, which makes Mabel-Bill laugh. “I beat you once, I can do it again. Just like I’m going to have to do now.”

Instead of looking cowed, or even the smallest bit threatened, the look on Mabel’s face is smug. Dipper tries very hard not to feel like he’s making a mistake here. Is it really a trap if you know it’s been set for you?

Okay, yes, but with knowledge of it, he has the resources to escape it much easier. Right?

“Whatever.” Dipper’s face is getting red and he hates it. He sticks out a hand. “Deal?”

Mabel-Bill takes it. Except, this time, Dipper isn’t being pulled out of his body.

He finds himself yelping as he’s pushed to the ground. Blinking away the black spots that flash across his vision, Dipper gapes at the sight of his sister straddling his lap. His mouth is still ajar when Mabel-Bill says, “Let’s seal this deal the old-fashioned way.”

Mabel’s face comes worryingly – because it’s not really _her_ – close to Dipper’s own. Those hands, normally small and even comforting to feel, alarm Dipper when they quickly dart in to grasp his cheeks. He tries to turn away, but the grip is surprisingly strong, and he’s left unable to move or pull away. Left cornered and confused. So, so, so confused.

Mabel’s eyes are unnaturally wide, smile just as so.

“With a _kiss_.”

“No, no, no _no nonono_ —” Dipper starts to protest, heart shuddering and dropping straight through him. But Mabel – Bill plunges forward anyway, pressing Mabel’s – not Mabel’s – soft lips to Dipper’s own.

Weird, it’s weird, too weird; wrong, this is so wrong –

A thumb presses on his jaw and in pain, he gasps, opens his mouth –

A tongue –

Mabel’s – not Mabel’s – tongue –

All over the inside of his mouth, his lips, his teeth, the roof, _his own_ –

So wrong, this is so, so _wrong_ –

He can’t breathe –

Bill – because it’s _not Mabel_ – finally pulls back, looking horrifically pleased with himself. Mouth shiny with spit – some of which is Dipper’s own, he’s sure. Chirps out a bright, “Deal!”

Between trembling gasps to desperately suck in some air, Dipper lets out a weak, “What the hell?” He’s so confused, as to what – as to _everything_. What – what even –?

“ _Dipper_ ,” chides a scandalized voice, and he freezes, because that’s Mabel, that’s _actually his sister_ –

But then she’s saying, back to Bill’s inflections, “You kiss your sister with that mouth?”

And that. That fills Dipper with absolute rage. More than anything he thinks he’s felt in a long time. More than he’s ever felt towards his sister in a poor moment. More than he’s ever felt towards his parents or other adult figures for being unfair. More than any bully he’s had to deal with.

_How dare he? How **dare** he?_

His blood rushes through him, hot and angry, seizing his veins like magma. He is livid and ready to _spit_ –

But before he can so much as utter a sound, Bill sets Mabel’s hands on his shoulders and shoves him back –

But he’s not falling, because –

Not Mabel is

Falling

Through

Him

And when he looks down at his hand, it’s transparent and wispy. He doesn’t have to stick it in his own gut to know he’s discorporal again. Again. Isn’t that a weird thing to think about? Not only is he a ghost, but for the second time.

It’s all this monster’s fault.

A few minutes ago, Dipper had a plan. Yet, now, he’s sitting here, on a complete other plane as he looks onto the one he’s been ejected from. He looks down at his own body, the one Bill is now inhabiting, as it cackles and rolls around on the ground in evil, unmitigated glee. Beside it, his sister’s own is sprawled about, knocked out cold.

Dipper’s own head, where he should have a plan cooking, a way to stop this, is blank.

Man _… not again_.


End file.
